Advantages and Disadvantages of Galvanized ERW Pipe

What is galvanized erw pipe?
 
Galvanized erw pipe, that is, galvanized high-frequency straight seam electric resistance welded steel pipe, is a kind of pipe obtained by galvanizing the surface of high-frequency straight seam electric resistance welded steel pipe (erw pipe). It is formed by rolling and welding steel plates, and a dense zinc layer is formed on the surface through galvanizing, which effectively isolates air and moisture, significantly improves corrosion resistance, and extends the service life several times longer than ordinary erw pipes.
 
Compared with ordinary erw pipes, galvanized erw pipes have a bright silvery-white appearance, are both decorative and practical, can adapt to complex environments such as humidity, acid and alkali, and are widely used in building water supply and drainage, fire protection pipes, greenhouse supports and other fields. However, special treatment is required during welding to avoid the influence of the zinc layer, and there is a risk of the zinc layer falling off under strong external force or extreme corrosion.
 
Difference from ordinary erw pipe
 
1. Appearance and corrosion resistance
From the appearance, the galvanized erw pipe has a unique silver-white metallic luster due to the zinc layer on the surface. The color is uniform and has a certain reflectivity. It looks particularly bright under the light. The ordinary erw pipe is the original color of the steel, mostly dark gray, and the surface is relatively monotonous. In terms of corrosion resistance, there is a world of difference between the two.
The zinc layer of the galvanized erw pipe is like a solid layer of armor. When exposed to the air, the zinc layer will first react with oxygen to form a dense zinc oxide protective film. This protective film can effectively prevent oxygen and moisture from further corroding the steel pipe matrix, thereby greatly extending the service life of the steel pipe. 
Ordinary erw pipes do not have this layer of protection. Once they come into contact with humid air or corrosive media, they will easily rust, and mottled rust will gradually appear on the surface. As time goes by, the degree of rust will continue to deepen, seriously affecting its performance and service life.
 
2. Performance and application scenarios
In terms of performance, although the strength and toughness of galvanized erw pipes will be slightly reduced after galvanizing, this change is very small and can be almost ignored in most practical applications. Ordinary erw pipes maintain their original mechanical properties, with relatively high strength and toughness. However, there are obvious differences between the two in terms of application scenarios.
Galvanized erw pipes, with their excellent anti-corrosion properties, perform well in some environments with high anti-corrosion requirements, such as chemical industry, building water supply and drainage, fire protection pipelines and other fields. They can operate stably in harsh corrosive environments to ensure the safety and reliability of the pipeline system. Ordinary erw pipes are more suitable for occasions that do not require high corrosion protection but have relatively high requirements for strength and toughness, such as mechanical structure manufacturing, general fluid transportation, etc.
 
Advantages of galvanized erw pipe
 
1. Strong corrosion resistance
The most notable advantage of galvanized erw pipe is its excellent corrosion resistance. In humid environments, such as construction projects in coastal areas, ordinary steel pipes may rust in a short time. However, the zinc layer on the surface of galvanized erw pipes can effectively resist the erosion of humid air and salt, and can be used for decades without serious corrosion. In the chemical industry, facing various acid and alkali media, galvanized erw pipes also perform well, can operate stably, and ensure the smooth progress of chemical production, greatly extending the service life of the pipeline system and reducing the cost and trouble of replacing pipelines.
 
2. Beautiful appearance
The surface of the galvanized erw pipe is smooth and bright, showing a uniform silver-white metallic luster and has a certain decorative effect. In some construction projects that require a certain appearance, such as exposed pipes in commercial buildings, supporting structures in landscape facilities, etc., galvanized erw pipes can not only meet functional requirements, but also enhance the overall visual effect, adding a sense of modernity and sophistication to the building.
 
3. Cost Advantage
Although the production process of galvanized erw pipe is relatively complicated, involving multiple links such as high-frequency welding and galvanizing, it has a high cost-effectiveness in terms of long-term use cost. Due to its excellent corrosion resistance, the frequency of maintenance and replacement is greatly reduced during use. Compared with ordinary steel pipes, galvanized erw pipes do not require frequent anti-corrosion treatment and replacement during their service life, saving a lot of manpower, material and financial resources, and have obvious comprehensive cost advantages. This is one of the important reasons why they are widely used in many fields.
 
Disadvantages of galvanized erw pipe
 
1. Risk of zinc layer falling off
Although the zinc layer of galvanized erw pipes provides good protection against corrosion, there is a risk of the zinc layer falling off under certain conditions. Once the zinc layer falls off, the anti-corrosion ability of the steel pipe will be greatly reduced, and it will be prone to rust and corrosion, affecting its service life and performance.
 
2. Welding becomes more difficult
Welding is a common operation during pipeline installation and connection, but the welding difficulty of galvanized erw pipe is increased compared with ordinary erw pipe. During the welding process, the zinc layer will cause a series of problems. Due to the relatively low melting point of zinc, the zinc layer will quickly melt and evaporate at the high temperature of welding, producing a large amount of zinc vapor. These zinc vapors will form pores in the weld, reducing the density and strength of the weld.
 
3. Complex production process
The production process of galvanized erw pipe is relatively complicated, which is also a disadvantage. During the production process, in addition to the high-frequency straight seam resistance welding forming process, galvanizing is also required. The entire production process involves many steps, and each link requires strict control of process parameters, which not only increases production costs, but also affects production efficiency to a certain extent. Compared with ordinary erw pipes, the production cycle of galvanized erw pipes is longer, and it is relatively difficult to increase production capacity.
 
Conclusion
 
Galvanized erw pipe, as a specially treated pipe, has significant advantages such as strong corrosion resistance, beautiful appearance and cost advantage, and plays an important role in many fields such as construction and chemical industry. However, it also has disadvantages such as the risk of zinc layer falling off, increased welding difficulty and complex production process. In actual applications, users should weigh the advantages and disadvantages and carefully choose whether to use galvanized erw pipes based on specific needs and usage environment.

Read more: Galvanized ERW Pipe: the All-rounder of Industrial Pipes